Strain-relief device for cables and wire-guiding element

ABSTRACT

A strain-relief device for cables, in particular optical waveguide cables, includes a lower part ( 10 ), which is in the form of a U in cross section, and an upper part ( 30 ). The lower part ( 10 ) is formed on its limbs ( 12 ) on one end side ( 16 ) with a pivot bearing and on the opposite end side ( 13 ) with latching tabs ( 14 ), which are arranged on the inner sides of the limbs ( 12 ). The upper part ( 30 ) includes at least two sprung lateral limbs ( 31 ), on whose outer side in each case at least one latching projection ( 35 ) is arranged, which latching projections ( 35 ), in the assembled state, latch behind the latching tabs ( 14 ) on the lower part ( 10 ). The upper part ( 30 ) also includes spindle means, which can be inserted into the pivot bearing in the lower part ( 10 ), and to a wire-guiding element ( 60 ), in particular for optical waveguide wires. The wire-guiding element ( 60 ) includes a lower part ( 40 ) and an upper part ( 50 ). The lower part ( 40 ) is formed in the longitudinal direction (L) with guides ( 46 ), which are formed between guide webs ( 45 ), clamping ribs ( 47 ) being arranged on the inner sides of the guide webs ( 45 ), and having first fixing means on the upper side ( 44 ). The upper part ( 50 ) has second fixing means on its lower side ( 51 ) which produce a connection with the first fixing means.

The invention relates to a strain-relief device for cables, inparticular optical waveguide cables, and to a wire-guiding element, inparticular for optical waveguide wires.

Strain-relief devices for cables are known in various embodiments. Acommon problem with strain-relief devices is that they are not veryuser-friendly if further cables are additionally intended to beconnected as well, subsequently.

The invention is therefore based on the technical problem of providing astrain-relief device for cables, in particular optical waveguide cables,which makes subsequent fixing of cables easier. A further technicalproblem is that of providing a wire-guiding element, in particular foroptical waveguide wires, which simplifies subsequent changes to thewires to be guided.

In this regard, the strain-relief device for cables comprises a lowerpart, which is in the form of a U in cross section, and an upper part,the lower part being formed on its limbs on one end side with a pivotbearing and on the opposite end side with latching tabs, which arearranged on the inner sides of the limbs, the upper part comprising atleast two sprung lateral limbs, on whose outer side in each case atleast one latching projection is arranged, which latching projections,in the assembled state, latch behind the latching tabs on the lowerpart, and comprising spindle means, which can be inserted into the pivotbearing in the lower part, the connection between the spindle means andthe pivot bearing preferably being detachable.

As a result, a strain-relief device which can be manipulated in a verysimple manner is provided. In this regard, the cable to be fixed isinserted into the U-shaped lower part, then the upper part with thespindle means is inserted into the pivot bearing, and the upper part ispushed down, as a result of which it latches with the latchingprojections on the latching tabs and in the process fixedly clamps thecable. In order to release the connection, for example in order to fix afurther cable, the two sprung lateral limbs are pushed together inward,as a result of which the latching projections are guided laterally pastthe latching tabs and the upper part can be pivoted upward again. A newcable can then be inserted and the upper part pushed down again. Owingto the removal of the upper part, in this case the procedure can befacilitated since the new cable can now be inserted into the U-shapedlower part from above.

In a preferred embodiment, in each case at least two latchingprojections are arranged on the outer side of the sprung lateral limbs.This makes it possible to securely fix cables having different diametersor a different number of cables.

In a further preferred embodiment, the pivot bearing is in the form of acylindrical opening with a gap toward the upper side of the limb and thespindle means is in the form of a web. In this case, the web is matchedto the width of the gap, with the result that it can be guided throughthe gap into the opening. This means that the upper part can only beremoved in a position in which the web and the gap are aligned and isotherwise connected to the lower part in a manner in which it cannot bereleased.

In a further preferred embodiment, a bow-shaped element is arrangedabove the two sprung lateral limbs and/or a sprung, plate-shaped elementis arranged underneath, the sprung lateral limbs protruding at theirfree end beyond the bow-shaped element and the plate-shaped element. Inthis case, the plate-shaped element acts as a contact-pressure plate forthe cables, the bow-shaped element being used to press the upper partdown. As a result of the fact that the sprung lateral limbs protrudebeyond the bow-shaped element and the plate-shaped element, they canstill be gripped and pushed together easily in the assembled state.Owing to the sprung, plate-shaped element, any desired cable diametersare securely clamped since the latching projections on their own onlyform rough latching.

In a further preferred embodiment, the plate-shaped element hasclearances, with the result that, when the upper part is pressed down,the plate-shaped element slides past the latching tabs of the lowerpart.

In a further preferred embodiment, the plate-shaped element is formed onits lower side with transverse ribs, which improve the contact-pressureagainst the cable and counteract a tensile force.

In a further preferred embodiment, a further plate-shaped element with asprung cut-free portion is arranged on the lower side of the lower part,by means of which cut-free portion the strain-relief device can be fixedin a slit. However, in principle other fixing means are also possible.

The wire-guiding element comprises a lower part and an upper part, thelower part being formed in the longitudinal direction with guides, whichare formed between guide webs, clamping ribs being arranged on the innersides of the guide webs, and has first fixing means on the upper side,the upper part having second fixing means on its lower side whichproduce a connection with the first fixing means. As a result, verysimple fixing of the wires, in particular of optical waveguide wires, isachieved, in particular in combination with the strain-relief device asituation being achieved in which the wires do not run in an undefinedmanner when the strain-relief device is opened. Optical waveguide wiresare in this case understood to mean optical waveguide fibers with aseparate sheathing.

Preferably, the first fixing means are in the form of holes, and thesecond fixing means are in the form of pins or knobs, or vice versa.

Further preferably, at least one hole is in the form of a slot in orderto compensate for tolerances between the upper part and the lower part.

In a further preferred embodiment, the upper part has further firstfixing means and guide webs on its upper side, which makes it possibleto stack a plurality of wire-guiding elements one above the other, whichis of particular advantage when further cables are additionally beingfixed.

In a further preferred embodiment, a plate-shaped element with a sprungcut-free portion is arranged on the lower side of the lower part.

The invention will be explained in more detail below with reference to apreferred exemplary embodiment. In the figures:

FIG. 1 shows a perspective illustration of a lower part of astrain-relief device,

FIG. 2 shows a perspective illustration of an upper part of astrain-relief device,

FIG. 3 shows a perspective illustration of the strain-relief device inthe assembled state with a cable clamped in,

FIG. 4 shows a perspective plan view of a lower part of a wire-guidingelement,

FIG. 5 shows a perspective view from below of an upper part of awire-guiding element,

FIG. 6 shows a perspective plan view of the upper part of thewire-guiding element, and

FIG. 7 shows a perspective illustration of an assembled, stackedwire-guiding element.

FIG. 1 illustrates a lower part 10 of a strain-relief device 1 forcables 2. The lower part 10 has a base 11, on which two limbs 12 arearranged, with the result that the lower part 10 has a U-shaped crosssection. Two latching tabs 14, which extend inward from the upper side15 of the lower part 10, are arranged on one end side 13 of the lowerpart 10 on the inner sides of the limbs 12. Two continuous cylindricalopenings 17 are incorporated in the limbs 12 on an opposite end side 16,the cylindrical openings being open toward the upper side 15 by a gap18. A plate-shaped element 20, which extends in the longitudinaldirection L, is arranged on the lower side 19 of the base 11. In thiscase, the plate-shaped element 20 is formed at a right angle to thelower side 19. A sprung element 21 is cut free from the plate-shapedelement 20 by means of free-punching. The illustrated lower part 10 ispreferably produced integrally from plastic.

FIG. 2 illustrates an upper part 30 of a strain-relief device. The upperpart 30 comprises two sprung lateral limbs 31, a bow-shaped element 32and a sprung, plate-shaped element 33, which are all integrallyconnected to one another. At their free ends 34, in this case the twosprung lateral limbs 31 protrude beyond the bow-shaped element 32 andthe plate-shaped element 33, respectively. In each case three latchingprojections 35 are arranged on the outer sides of the sprung laterallimbs 31.

In each case one web 36, whose width B is smaller than the width of thegap 18, is arranged on the side opposite the free ends 34 on the outersides of the sprung lateral limbs 31. The thickness of the sprunglateral limbs 31 tapers in the direction toward the free ends 34. Theplate-shaped element 33 has two clearances 37. Furthermore, fourtransverse ribs 39, which run away from the lower side 38 to a point,are arranged on the lower side 38.

In order to fix a cable 2, said cable is laid in the longitudinaldirection L on the base 11 of the lower part 10. Then, the two webs 36are inserted into the opening 17 through the gap 18, and the bow-shapedelement 32 is pushed downward. In the process, the plate-shaped element33 runs with its clearances 37 past the latching tabs 14. If thebow-shaped element 32 is pushed further downward, at first the lowermostlatching projections 35 latch under the latching tabs 14. Depending onthe thickness of the cable 2 or on the number of cables 2 in the lowerpart 10, the bow-shaped element 32 can then be pushed down furtherstill, with the result that the central or even the upper latchingprojections 35 may engage behind the latching tabs 14. Owing to thesprung, plate-shaped element 33, in this case sufficient force isexerted on the cable 2 for fixing it securely. The completely assembledstate is illustrated in FIG. 3, wherein an individual optical waveguidewire 3 is illustrated as being passed out of the cable 2. Thestrain-relief device can then be plugged into a slit via theplate-shaped element 20 and latched by means of the sprung element 21.In order to unlatch the upper part 30 of the strain-relief device 1, thetwo sprung lateral limbs 31 are pushed together inward, with the resultthat the latching projections 35 slide laterally past the latching tabs14 and the bow-shaped element 32 can be pivoted upward again without anyresistance.

FIG. 4 illustrates a lower part 40 of a wire-guiding element 60. Again aplate-shaped element 42 with a sprung element 43 is arranged on thelower side 41, it being possible for reference to be made to theembodiments in relation to the strain-relief device 1 as regards theoperation. Five guide webs 45 are arranged on the upper side 44, the twoouter guide webs being wider than the inner guide webs 45. Guides 46,into which wires to be fixed can be inserted, are formed between theguide webs 45. Clamping ribs 47 are arranged on the inner sides of theguide webs 45, preferably arranged alternately on the left-hand andright-hand guide web 45 of a guide 46. Holes 48, 49 are introduced intothe wider guide webs 45, which holes are used as first fixing means, thehole 49 being in the form of a slot.

FIGS. 5 and 6 illustrate an upper part 50 of the wire-guiding element60, the lower side 51 virtually being a plane and only being interruptedby two knobs 52. The upper part 50 and the lower part 40 are connectedto one another via the knobs 52, which represent second fixing means, bythe knobs 52 being plugged into the holes 48, 49. On the upper side 53,the upper part has a similar structure to the upper side 44 of the lowerpart 40, namely guide webs 54, guides 55, clamping ribs 56 and holes 57.This makes it possible to arrange a plurality of upper parts 50 oneabove the other, which is illustrated in FIG. 7. In this case, fouroptical waveguide wires 3 are fixed in each upper part 50. Any desirednumber of optical waveguide fibers 3 can therefore be guided one abovethe other in a plurality of planes, according to the number of upperparts 50.

LIST OF REFERENCE SYMBOLS

-   1 Strain-relief device-   2 Cable-   3 Optical waveguide wire-   10 Lower part-   11 Base-   12 Limb-   13 End side-   14 Latching tabs-   15 Upper side-   16 End side-   17 Opening-   18 Gap-   19 Lower side-   20 Plate-shaped element-   21 Sprung element-   30 Upper part-   31 Sprung lateral limbs-   32 Bow-shaped element-   33 Plate-shaped element-   34 Free ends-   35 Latching projection-   36 Web-   37 Clearance-   38 Lower side-   39 Transverse rib-   40 Lower part-   41 Lower side-   42 Plate-shaped element-   43 Sprung element-   44 Upper side-   45 Guide web-   46 Guide-   47 Clamping rib-   48, 49 Hole-   50 Upper part-   51 Lower side-   52 Knobs-   53 Upper side-   54 Guide web-   55 Guide-   56 Clamping rib-   57 Hole-   60 Wire-guiding element-   B Width-   L Longitudinal direction

1. A strain-relief device for cables, the strain-relief devicecomprising: a lower part, which is in the form of a U in cross section,and an upper part, the lower part including limbs that define a pivotbearing at one end and that define latching tabs at an opposite end, thelatching tabs being arranged on inner sides of the limbs, and the upperpart including at least two sprung lateral limbs, a bow-shaped element,and a plate-shaped element that extend from a first side of the upperpart to a second side of the upper part, at least one latchingprojection being arranged on an outer side of each lateral limb, whichlatching projections, in an assembled state, latch behind the latchingtabs on the lower part, and the upper part including spindle means,which is configured to be inserted into the pivot bearing in the lowerpart; wherein the bow-shaped element is arranged above the two sprunglateral limbs and the plate-shaped element is arranged underneath thetwo sprung lateral limbs.
 2. The strain-relief device as claimed inclaim 1, wherein in each case at least two latching projections arearranged on the outer side of each sprung lateral limb.
 3. Thestrain-relief device as claimed in claim 1, wherein the pivot bearing isin the form of a cylindrical opening with a gap toward an upper side ofeach limb, and the spindle means is in the form of a web.
 4. Thestrain-relief device as claimed in claim 1, wherein free ends of thelateral limbs protrude beyond the bow-shaped element and theplate-shaped element.
 5. The strain-relief device as claimed in claim 4,wherein the plate-shaped element defines slots.
 6. The strain-reliefdevice as claimed in claim 4, wherein the plate-shaped element is formedon its lower side with transverse ribs.
 7. The strain-relief device asclaimed in claim 1, wherein a further plate-shaped element with a sprungcut-free portion is arranged on a lower side of the lower part.
 8. Astrain-relief device for cables, the strain-relief device comprising: alower part including a first base, a first limb, and a second limb, thelimbs extending upwardly from the first base to define a U-shaped crosssection, the lower part having a first end and a second end, the firstand second limbs including latching tabs at the first end of the lowerpart, the first and second limbs defining a pivot bearing at the secondend of the lower part; and an upper part including a first deflectingmember and a second deflecting member extending from a second base, thefirst and second deflecting members each defining a plurality oflatching projections at exterior surfaces thereof, each of the latchingprojections being configured to engage the latching tabs of the lowerpart, the second base defining a spindle configured to cooperate withthe pivot bearing to enable the upper part to pivot relative to thelower part; wherein the upper part also includes a bow-shaped memberextending from the second base, the bow-shaped element being spaced fromand oriented transverse to the first and second members; wherein theupper part also includes a plate-shaped member extending from the secondbase opposite the bow-shaped member; and wherein the plate-shaped memberdefines clearances that are sized and configured to enable the latchingtabs of the lower part to pass through the clearances.
 9. Thestrain-relief device as claimed in claim 8, wherein each of the firstand second deflecting members defines three latching projections. 10.The strain-relief device as claimed in claim 8, wherein the pivotbearing defines an opening in each limb of the lower part at the secondend.
 11. The strain-relief device as claimed in claim 10, wherein eachlimb also defines a gap at the second end extending between the openingand a periphery of the limb.
 12. The strain-relief device as claimed inclaim 11, wherein the spindle includes webs extending outwardly fromopposite sides of the second base, wherein each web is configured toslide through the gap in one of the limbs to fit within the respectiveopening.
 13. The strain-relief device as claimed in claim 8, whereinfree ends of the first and second members extend beyond the bow-shapedmember.
 14. The strain-relief device as claimed in claim 8, wherein alower side of the plate-shaped member defines transverse ribs.
 15. Thestrain-relief device as claimed in claim 8, wherein the lower partincludes a plate-shaped element extending in an opposite direction fromthe first and second limbs, the plate-shaped element including a springelement.